The winter white dwarf hamster (''Phodopus sungorus''), also known as the Russian dwarf hamster, Djungarian hamster, striped dwarf hamster, Siberian hamster, or Siberian dwarf hamster, is one of three species of hamster in the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Phodopus
''Phodopus'', a genus of rodents in the hamster subfamily Cricetinae—a division of the larger family Cricetidae—is a lineage of small hamsters native to central Asia that display unusual adaptations to extreme temperatures. They are the only ...
''. It is ball-shaped and typically half the size of the
Syrian hamster
The golden hamster or Syrian hamster (''Mesocricetus auratus'') is a rodent belonging to the hamster subfamily, Cricetinae. Their natural geographical range is in an arid region of northern Syria and southern Turkey. Their numbers have been d ...
, so is called a dwarf hamster along with all ''Phodopus'' species. Features of the winter white hamster include a typically thick, dark grey dorsal stripe and furry feet. As winter approaches and the days shorten, the winter white dwarf hamster's dark fur is almost entirely replaced with white fur. In captivity, this does not usually happen as animals maintained as pets are generally housed indoors and exposed to artificial light that prevents the recognition of short winter daylengths. In the wild, they originate from the
wheat fields of
Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
, the
meadows
A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non-woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or artifici ...
of
Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...
and
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
, and the birch stands of
Manchuria
Manchuria is an exonym (derived from the endo demonym " Manchu") for a historical and geographic region in Northeast Asia encompassing the entirety of present-day Northeast China (Inner Manchuria) and parts of the Russian Far East (Outer Manc ...
.
Winter white dwarf hamsters are common as pets in Europe and North America, and exhibit greater variance in their coats than those found in the wild. They reproduce often—more so than
Syrian hamster
The golden hamster or Syrian hamster (''Mesocricetus auratus'') is a rodent belonging to the hamster subfamily, Cricetinae. Their natural geographical range is in an arid region of northern Syria and southern Turkey. Their numbers have been d ...
s, and as they have no fixed breeding season, can continue to produce some numbers of offspring all year round. Young pups act aggressively to one another, while breeding females may show similar aggression to males. The winter white is known to be one of the most tameable types of hamsters.
Naming
The hamster has no fully accepted common name, winter white dwarf hamster and Russian dwarf hamster are among the most often used. Confusion arises because of their physical similarity to
Campbell's dwarf hamster
Campbell's dwarf hamster (''Phodopus campbelli'') is a species of hamster in the genus ''Phodopus''. It was given its common name by Oldfield Thomas in honor of Charles William Campbell, who collected the first specimen in Mongolia on July 1, 1 ...
, consequently, the name Djungarian hamster and Russian dwarf can refer to both winter white and Campbell's dwarf hamsters. The term "winter white" derives from the fact that in the wild the hamster changes its fur colour to white for the winter months, this camouflages the hamster and reduces
predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
when snow is on the ground. Campbell's dwarf hamsters do not change fur colour during the winter and can only be described as being "winter white" erroneously.
The
binomial name
In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...
for the hamster is ''Phodopus sungorus''. The hamster was first described by
Peter Simon Pallas
Peter Simon Pallas Fellow of the Royal Society, FRS FRSE (22 September 1741 – 8 September 1811) was a Prussian zoologist and botanist who worked in Russia between 1767 and 1810.
Life and work
Peter Simon Pallas was born in Berlin, the son ...
in 1773 as a
mouse
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
. The name ''sungorus'' derives from the geographic region
Dzungaria
Dzungaria (; from the Mongolian language, Mongolian words , meaning 'left hand') is a geographical subregion in Northwest China that corresponds to the northern half of Xinjiang. It is thus also known as Beijiang, which means "Northern Xinjiang" ...
. In 1778, Pallas renamed the hamster to ''Mouse songarus''.
In 1912
Ned Hollister
Ned Hollister (November 26, 1876 – November 3, 1924) was an American biologist primarily known for studying mammals.
Hollister was born in Delavan, Wisconsin, to parents Kinner Newcomb Hollister (1841–1911) and Frances Margaret (Tilden) Hollis ...
ordered the "Mouse songarus" to the genus ''Phodopus''. A. I. Argiropulo, in 1933, changed the name to ''priority sungorus'' and determined the hamster as a
subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...
of Campbell's dwarf hamster called ''Phodopus sungorus sungorus''. Today winter white dwarf hamsters and Campbell's dwarf hamsters are considered separate species with the winter white officially known as ''Phodopus sungorus''.
Physical description
![Phodopus sungorus](https://upload.wikimedia.org/wikipedia/commons/5/5e/Phodopus_sungorus.jpg)
![Pearl Winter White Russian Dwarf Hamster - Front](https://upload.wikimedia.org/wikipedia/commons/d/de/Pearl_Winter_White_Russian_Dwarf_Hamster_-_Front.jpg)
![Winter White](https://upload.wikimedia.org/wikipedia/commons/9/9f/Winter_White.JPG)
The coat of the winter white dwarf hamster is less woolly than that of
Campbell's dwarf hamster
Campbell's dwarf hamster (''Phodopus campbelli'') is a species of hamster in the genus ''Phodopus''. It was given its common name by Oldfield Thomas in honor of Charles William Campbell, who collected the first specimen in Mongolia on July 1, 1 ...
,
[The Dwarf Hamster: A Guide to Selection, Housing, Care, Nutrition, Behaviour, Health, Breeding, Species and Colours (About Pets) ] and apart from the normal colouring, they can be coloured sapphire, sapphire pearl, or normal pearl. The head and body length of the winter white dwarf hamster is 70–90 mm, the length of the tail is 5–15 mm, and the hind legs are 11–15 mm.
[Winogradow und Argiropulo 1941. Zitiert in: Ross 1998 (S. 1, „General Characters“)][Krylzow und Schubin 1964. Zitiert in: Ross 1998 (S. 1, „General Characters“).] The
body weight
Human body weight is a person's mass or weight.
Strictly speaking, body weight is the measurement of weight without items located on the person. Practically though, body weight may be measured with clothes on, but without shoes or heavy accessor ...
changes dramatically throughout the year. It is at its lowest during the winter.
[Bartness & Wade, 1985. Photoperiodic control of seasonal body weight cycles in hamsters (Abstract)] In males, the body weight ranges from , and in females, .
In human care, they are slightly heavier. The average lifespan of the winter white dwarf hamster is one to three years in
captivity
Captivity, or being held captive, is a state wherein humans or other animals are confined to a particular space and prevented from leaving or moving freely. An example in humans is imprisonment. Prisoners of war are usually held in captivity by a ...
, though they can live longer. In the wild, they are known to live as little as one year.
In summer, the fur of the winter white hamster on the back changes from ash-grey to dark brown, or sometimes pale brown with a
tint
In color theory, a tint is a mixture of a color with white, which increases lightness, while a shade is a mixture with black, which increases darkness. Both processes affect the resulting color mixture's relative saturation. A tone is produc ...
.
[How to Care for Your Dwarf Hamster (Your first...series) ] The face changes to grey or brown, while the mouth area, the
whisker
Vibrissae (; singular: vibrissa; ), more generally called Whiskers, are a type of stiff, functional hair used by mammals to sense their environment. These hairs are finely specialised for this purpose, whereas other types of hair are coarser ...
area, and the ears are slightly brighter.
[Figala und Mitarbeiter 1973 (Abstract). Die Angaben beziehen sich auf unter natürlichen Bedingungen gehaltene Hamster.] The outer ears and the eyes have black edges. The rest of the head is dark brown or black. From the head to the tail runs a black-brown dorsal stripe.
[
Dissertation Quoted in Ross 1998 (p. 1, Diagnosis, General Characters "] The throat, belly, tail and limbs are white.
The ears are grey with a pinkish tint
with scattered black hairs. The hairs on the underside are completely white.
[
Quoted in Ross, 1998 (p. 1, "Context and Content" of the genre, "Diagnosis "]
The bright coat the bottom extends to the shoulders, flanks, and hips in three arches upward. It is distinguished from the darker fur on the top of the existing black-brown hair, three curved line.
Apart from the typical colouration, winter white dwarf hamsters can also be coloured pearl, sapphire, sapphire pearl, and marbled. Other colorations are available, but these are strongly suspected to appear only in hybrid crossings with Campbell's dwarf hamsters. Some of these colorations are mandarin, blue, argente, yellow blue fawn, camel, brown, cream, merle, and umbrous.
In the winter, the fur is more
dense
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematically ...
.
They sometimes have a grey tint on their heads.
More than 10% of the hamsters kept in the first winter develop the summer coat. In the second winter, only a few change into the winter coat and winter colour is less pronounced. The
moulting
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...
in the winter fur starts in October or November and is completed in December, while the summer coat begins in January or February and is completed in March or early April.
The ears are grey with a pinkish tint.
Moulting both run jobs on the head and the back of the spine to the sides, the legs and the underside. The hairs grow longer in the summer, to about ten millimetres long.
The
pigmentation
A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compo ...
of hair is controlled by the hormone
prolactin
Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pit ...
and colour
genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar wor ...
.
Day length can be less than 14 hours to initiate the change to winter coat, though it is possible they may be able to sense a directional change in photoperiod length, such as in one experiment that demonstrated a transition from 16 hours of light to 14 hours initiates a change to the winter coat. The change to the winter coat can be triggered in the summer by the short day lengths. The change occurs back to the summer coat in the autumn, when the length of the days change again. At internal temperatures hamsters in captivity start later with the changes. The winter colour is less pronounced in them.
The eyes of the winter white hamster are black, unless it is
albino
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino.
Varied use and interpretation of the term ...
in which case they are red.
In the wild
![Pallas PS by Tardier grey](https://upload.wikimedia.org/wikipedia/commons/2/2c/Pallas_PS_by_Tardier_grey.jpg)
In the wild, the hamster's fur changes colour in the winter. This adaptation helps them to evade predators in the snow-covered steppes.
The hamster digs tunnels one metre deep leading to ground burrows where they can sleep, raise their young and hide from predators.
The
weasel
Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets and European mink. Members of this genus are small, active predators, with long and slender bo ...
is one of the hamster's main predators.
Most of these burrows have six entrances. In the summer, the burrows are lined with moss. To keep the burrow warm in the winter, the hamster closes all but one entrance and lines the burrows with animal fur or
wool
Wool is the textile fibre obtained from sheep and other mammals, especially goats, rabbits, and camelids. The term may also refer to inorganic materials, such as mineral wool and glass wool, that have properties similar to animal wool.
As ...
that it finds. The temperature inside the burrow is usually .
The hamsters sometimes live in the
semidesert
A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...
s in Central
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...
.
[Boris Stepanovich Yudin, Lijana Ivanova Galkina, Antonina Fedorovna Potapkina 1979 Quoted in Ross 1998 (p. 5, "Ecology ").] They also live in the dry steppes and wheat or
alfalfa
Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as w ...
fields, as well as on small fields in the forests of the region around
Minusinsk
Minusinsk (russian: Минуси́нск; kjh, Минсуғ) is a historical types of inhabited localities in Russia, town in Krasnoyarsk Krai, Russia. Population: 44,500 (1973).
Geography
Minusinsk marks the center of the Minusinsk Hollow ...
. The fur on the hamster's feet protect the feet from the cold ground in the cold climates in the wild.
The
population density
Population density (in agriculture: standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical term.Matt RosenberPopul ...
is highly varied.
In 1968, the first four examples of the hamster were caught in Western Siberia and brought to the
Max Planck Institute
Max or MAX may refer to:
Animals
* Max (dog) (1983–2013), at one time purported to be the world's oldest living dog
* Max (English Springer Spaniel), the first pet dog to win the PDSA Order of Merit (animal equivalent of OBE)
* Max (gorilla) (1 ...
in
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
.
Pet ownership
The hamsters are often found on the pet market in Europe, Japan, and North America.
Care of the hamster is similar to all other species of ''Phodopus''.
The hamsters, along with most rodents, are prone to
tumours
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
. They can also receive injury in the cheek pouch by sharp objects damaging the fragile inner lining. Other health problems include bite wounds, broken teeth,
constipation
Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement ...
,
dehydration
In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...
,
dental malocclusion
In orthodontics, a malocclusion is a misalignment or incorrect relation between the teeth of the upper and lower dental arches when they approach each other as the jaws close. The English-language term dates from 1864; Edward Angle (1855-1930), ...
, diarrhea, and ear problems.
[Dwarf Hamsters: Everything about Purchase, Care, Nutrition, and Behavior (Barron's Complete Pet Owner's Manuals) ]
Breeding
Winter white dwarf hamsters reproduce at a faster rate than Syrian hamsters.
''Phodopus'' species are able to become pregnant again on the same day that they have given birth. This can all happen within a 36-day period. This is done as a survival strategy to produce large numbers of offspring in a short period of time. This places tremendous demands on the mother.
Research suggests biparental care in Campbell's hamsters (''P. campbelli'') but not in winter white hamsters (''P. sungorus''). Frequent fighting can occur between the pups and as soon as they are weaned from their mother, they are separated from her. Most of the dwarf hamsters grow to 3 to 4" long. Hamsters maintained indoors that get artificial illumination during autumn and winter are likely to breed all year round, whereas in the wild and in animals maintained in captivity but under entirely natural light-dark cycles, breeding is restricted to the long days of spring and summer.
During the breeding time, the hamster may become aggressive. After mating, the female may want to attack the male to protect her babies. The male usually hides in holes or caves to escape the vicious bite of the female. The hamster's
estrous
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous p ...
cycle lasts four days; every four days, the female may accept the male back to breed again. This usually occurs when the darkness of the evening sets in. If male and female hamsters are not housed together from a young age, determining if the female is willing to breed with the male is difficult.
Hybrids
Of the five species of hamsters kept commonly as pets, only Campbell's dwarf hamster and the winter white dwarf hamster are able to interbreed and produce live hybrid offspring. Although hybrids make suitable pets, the breeding of hybrids and
cloning
Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. In the field of biotechnology, cl ...
can cause health and reproduction problems. In addition, the widespread breeding and distribution of hybrids could threaten the existence of both pure species and subspecies of the ecosystem, resulting in only mongrels. Hybridizing causes each litter to become smaller and the young begin to form
congenital
A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...
problems.
Conservation status
This hamster is listed as of
Least Concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
by the
International Union for Conservation of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
(IUCN). The population and distribution size are large, and no major or widespread threats to the species are known. Population numbers in the wild are not recorded.
References
External links
*
{{Taxonbar, from=Q214633
Phodopus
Rodents of Asia
Mammals described in 1773
Mammals of Siberia
Taxa named by Peter Simon Pallas